Managing Endophthalmitis in Nigeria: Lessons from Two Challenging Cases

Introduction: Endophthalmitis is a dreaded complication of cataract surgery. While the management of endophthalmitis with standard antibiotic combinations often suffice, occasionally some cases are not amenable and require greater astuteness and insight in management. Cases: In the first case, a non-bacterial endophthalmitis was suspected when there was no response to standard antibiotics given twice. The patient responded dramatically to a single dose of intravitreal amphotericin B 5mcg in 0.1ml. However, no laboratory confirmation was obtained, hence diagnosis was based on trial of therapy.The second was a case of Vancomycin Resistant Enterococcus faecium Endophthalmitis (VRE Endophthalmitis). Diagnosis was made after lack of response to standard intravitreal antibiotics, Amikacin and Amphotericin B. Potassium hydroxide (KOH) preparation was suggestive of a gram-positive organism, but showed no hyphate forms. In the absence of a positive culture, a direct staining of the vitreous smear showed organisms identifiable as Enterococcus feacium. There was a regrowth of the organisms after two vitrectomies, and the organism responded to intravitreal 200 mcg/0.1ml of linezolid, one of the newer oxazo-lidinones. However, final vision was only Hand motion even though the vitreous was largely clear. Optical coherence tomography (OCT) revealed a residual central serous retinopathy which did not respond to anti-VEGF therapy. Conclusion: Endophthalmitis can be caused by organisms not sensitive to the usual antibiotics. Use can be made of the KOH test and direct smear of vitreous aspirate to assist with diagnosis. Linezolid is effective against Vancomycin Resistant Enterococci but may be associated with central serous retinopathy.